A number of years ago I made my own 12AU7 version of the Starving Student Millet Hybrid headphone amplifier. When the designs were first published using a 19J6 tube it was relatively easy to find them, but in recent years this has become much harder. To workaround this a number of designs using various other valves have been posted on forums.
Trawling through hundreds of pages of posts to find the details was tiresome and as I enjoyed the project I wanted to give back to the community. So, two years ago I created schematics of the variations and published them to GitHub.
I used KiCad to create the diagrams and published both the source files and rendered schematics. You can download the variations and diagrams from GitHub. Alternatively, you can download the lot as a zip file.